Contents
The Red-winged Blackbird in Tropical Marshes
Gordon H. Orians
The Spring Migration of Gambel's Sparrows through Southern Yukon Territory
Barbara B. Dewolfe, George C. West, and Leonard J. Peyton
Observations on the Behavior of the Andean Condor (vultur Gryphus)
Janet Gailey and Niels Bolwig
Studies of a Declining Population of Brown Pelicans in Northwestern Baja California
Joseph R. Jehl Jr.
The Breeding Season of a Parasitic Bird, the Brown-headed Cowbird, in Central California
Robert B. Payne
News and Notes
The Condor
Publications Received
The Condor
The Bulletin Board
The Condor
Covers
Back Matter (PDF)
The Condor
Front Matter (PDF)
The Condor
Short Communications
Development of Thermo-regulation in Mallard Ducklings
Patrick J. Caldwell
Dispersion of Female Blue Grouse during the Brood Season
Fred C. Zwickel
Notched Toe Pads in Climbing Oscines
George A. Clark Jr.
New Distributional Records of Breeding Mexican Ducks
Roy E. Tomlinson, Seymour H. Levy, and J. J. Levy
Autumn Concentrations of Bald Eagles in Glacier National Park
B. Riley Mccelland
Observations of Wild Hybrids Between Canada and Blue Geese
J. P. Prevett and C. D. Macinnes
Vocal Stimulation in the Great Horned Owl
John T. Emlen
Differential Predation by South Polar Skuas in an Adelie Penguin Rookery
Dietland Muller-Schwarze and Christine Muller-Schwarze
Further Notes on the Western Grebe in Mexico
Robert W. Dickerman
Re-evaluation of Some Montana Bird Records
P. D. Skaar, Roger B. Clapp, and Richard C. Banks